I. Field of the Invention
The present invention relates generally to the loading, transportation, and unloading of pipe and tubing, and more particularly to devices used to transport such pipe and tubing.
II. Background and Prior Art
In the oilfield industry and many other industries, a wide variety of pipes and tubes (hereinafter “tubulars”) are used. Tubulars are often loaded directly onto flatbed trailers and stacked with divider boards in between the layers, and they are typically retained on the trailer by a series of vertical posts inserted into the outer edge of the trailer. When the tubulars are loaded or unloaded, they are moved only a few items at a time by forklift or crane, each time having to raise the tubulars above the side posts to clear the trailer. If the tubulars are being unloaded for use at their final destination, they are usually moved onto nearby pipe racks and stacked in similar fashion. This method of loading and unloading is widely accepted as the way such tasks must be performed, but it is a slow process, particularly when multimodal forms of transportation are required or when the tubulars must be moved several times before reaching their final destination.
For example, a typical sequence of events for moving tubulars may involve the following steps: (1) removal from a supplier's pipe rack, (2) placement of the tubulars onto a flatbed trailer or transport to a ship, (3) removal of the tubulars from the flatbed trailer, (4) placing the tubulars on a pipe slinging rack for pre-slinging into manageable bundles, (5) loading the pre-slung bundles of tubulars into special divider racks which are set up on the ship for transportation to a site, such as an oil platform, (6) removal of the tubulars from the ship, and (7) placement of the tubulars onto a pipe rack on the oil platform. In the foregoing simple example, and at each step of the loading and unloading process, tubulars are moved only in small batches. The divider racks on the ship must be set up each time tubulars are transported, and the racks remain on the deck of the ship after tubular removal. Therefore, the deck of the ship is unusable for anything other than tubular transport for the return trip. It can readily be seen, therefore, that in more complex shipping arrangements, this manual handling process can take quite some time. This is particularly problematic when participants in the shipping process are not immediately ready to transport the items, and the tubulars must be removed from the previous vehicle and temporarily stored.
The disadvantages of the aforementioned methods are many. First, as explained in the preceding example, the process of carefully moving small numbers of items is exceedingly slow, especially when each load of tubulars on a vehicle is carried in several stacks. Second, because of the extensive amount of time required to manually move tubulars from place to place, it can be an unduly expensive operation. In smaller jobs requiring a relatively small number of items, the expense of moving tubulars is often prohibitively expensive. Finally, as loading and unloading frequency increases, so does the risk that accidents will happen as tubulars are moved. For example, the movement of pipes to and from pipe racks often requires a person on top of the pipe rack to assist the forklift or crane operator in nudging the pipes to and from the rack, many times leading to injuries from tripping or falling.
A solution to the current methods of moving tubulars must be directed toward shortening the time required to move a given batch of tubulars from one place to another, particularly when multiple transfers must occur. As explained above, reducing the loading and unloading time carries immediate benefits in terms of decreased cost and decreased risk of personal injury.
One attempt to solve the foregoing problems has been made by a company in Scotland, Ferguson Seacabs, Ltd., in the form of tubular transportation frames. Such frames are helpful in minimizing time and costs of shipping, because the tubulars are contained within a portable frame which can be moved as a unit to and from each transportation vehicle. Because the frame includes forklift tubes in the base, it reduces the use of cranes. The frames are stackable, and they permit the containment of differing sizes of tubulars within the same frame. However, the Ferguson frames have a number of notable deficiencies. First, there is no integrated winch and strap assembly for use in securing a loaded frame, ostensibly because it relies upon an upper bar to mechanically lock the tubulars in place. Second, it does not provide full-length support for longer tubulars, resulting in possible damage to the exposed ends of the tubulars and their threads. Third, the Ferguson frames are not structurally capable of handling larger payloads in the range of 50,000 pounds. Fourth, the reliance on a four-point contact as the frames are stacked is less preferable to a more stable and redundant arrangement. Fifth, the divider elements between layers of tubulars in the prior frames are elastomerically coated members which must be fabricated and supplied by the manufacturer, eliminating the option of using conventional and less expensive timber dividers. Finally, the Ferguson frames appear to be designed only for the transportation of tubulars, because there is no multi-purpose floor or other supporting surface to permit the transportation of other equipment.
Consequently, the present invention substantially improves upon the prior art by providing a complete, multilength tubular transporter which: (a) permits greater payloads, (b) includes more secure stackable features, (c) allows commonly available winching systems and dividers, (d) offers better protection for long tubulars, and (e) provides a multi-purpose floor for the transportation of a wide range of equipment and supplies.